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No. 12 Oklahoma State was happy to get back to football after a long week.

It came at Lamar's expense.

In front of a record crowd of 59,061 at the Cowboys' home opener, Jeremy Smith rushed for three first-half touchdowns and Josh Stewart returned a punt 67 yards for a score as Oklahoma State routed Lamar 59-3 on Saturday night.

"The crowd was a big factor for us," Stewart said. "The walk was super-packed. That was exciting to see, and it shows you that no matter what, Stillwater has got your back."

The buzz most of the week surrounded a Sports Illustrated series that detailed alleged misconduct in the football program dating to 2001. Oklahoma State officials have contacted the NCAA and launched their own investigation.

Oklahoma State coach Mike Gundy wasn't exactly thrilled with the performance against an overmatched Championships Subdivision school.

"I thought our guys played OK," Gundy said. "We were a little sluggish and maybe even sloppy at times. Offensively, we were pretty average. It was tough for our players, getting them motivated after halftime. They did OK."

Caleb Berry led the offense for Lamar (1-2), throwing for 114 yards on 18 of 38 passing.

"It was a great experience overall," said Berry, who also rushed for 16 yards. "We might not have executed like we wanted to on offense, but our guys played hard and with heart and I'm proud of them."

Oklahoma State (3-0) has now scored a total of 115 points in its last two games as it heads into a bye week that precedes their Big 12 Conference opener Sept. 28 at West Virginia.

One week after a near-perfect performance in which he completed 24 of 27 passes for 326 yards and four touchdowns, J.W. Walsh looked considerably more human. With 17 of 30 passing, for 181 yards and one touchdown, Walsh left the game midway through the third quarter.

"A little disappointed," Walsh said. "There were a lot of times where there were open guys and I just missed them. There were a lot of throws where I'd like to have back. But any time you get a 59-3 win, you can't be too disappointed."

Walsh's one touchdown was the result of a spectacular lunging catch by Blake Jackson in the end zone with 8:23 left in the third quarter, extending the lead to 45-3. Two other sure TD passes were incomplete, ruled pass interference penalties on the defense.

Oklahoma State enjoyed an outstanding day on special teams, as Stewart totaled 114 yards on three punt returns, including his TD early in the third quarter that gave the Cowboys a 38-3 lead.

"We worked all week hard on that punt return and it just worked out just as we practiced it," said Stewart, who also gained a team-high 49 yards on three receptions. "Knowing you have blockers that are going to block for you, it makes it easier on me."

Oklahoma State's offense clicked from the very start, scoring touchdowns on each of its first three possessions to take a 21-0 lead before the end of the opening quarter.

The Cowboys needed to punt just once and held a 31-0 lead when Lamar forced Oklahoma State's first turnover of the season late in the second quarter. Branden Thomas picked off Walsh's deep throw and returned it 25 yards to the OSU 30-yard-line. That led to Lamar's first points of the game, a Justin Stout 44-yard field goal as time expired in the first half.

"This is not just a Big 12 team, it's a very good Big 12 team," Lamar coach Ray Woodward said. "It's as good of an offense as I've seen in the country this year."

Lamar's best chance for a touchdown came early in the fourth quarter when they pushed all the way to the OSU 6-yard line. On a fourth-and-three, the Cardinals opted to go for it, but Berry's pass sailed over Kevin Johnson's head in the end zone.

"We got some exposure for our program," Woodward said. "We got to come up here and see what it's like to play in front of a crowd like this. There are a lot of positives from tonight, but the scoreboard wasn't one of them."

On the game's opening drive, Lamar moved the ball effectively, gaining 32 total yards to the OSU 43-yard-line, but when they went for it on fourth-and-3, Berry's pass attempt fell incomplete.

After that, the Cowboys proceeded to march downfield, taking a 7-0 lead on Desmond Roland's 2-yard touchdown run with 9:09 left in the first quarter and the rout was on.